I’ve been using a lot of Debian based distributions recently after half a year on Arch. The main thing I miss a lot is the AUR. The convenience of having all my packaged in one format is a huge reason why I use Arch. Is there anything like it for the AUR?
I also think that things like Flatpaks and Snaps could be useful, as I don’t really want to have tons of repositories for tons of programs I install.
You could use distrobox to run an arch container and access the AUR directly.
https://github.com/89luca89/distrobox
It’s what I use for some applications on Kinoite.
AUR like stuff is simply not for Debian. You are expected to only use software in the official repos.
If you want AUR you should really use Arch Linux or a easier alternative like EndeavourOS.
If you really want AUR (like thing) on Debian I recommend the nix package manager. It will do it’s own thing without messing with the host OS.
Take a look at the nix package manager. It is a very large and up-to-date package repo.